Goldmining and ecosystem disruption in the Amazon: Impacts on vulnerable communities and environmental restoration

For the last 50 years, goldmining has introduced large amounts of mercury to the Amazonian environment. This highly toxic contaminant spreads widely and undergoes biomagnification through the region's complex food web, ultimately reaching Indigenous and riparian communities that are already heavily exposed. Some indigenous ethnic groups rely on fish as their primary source of proteins, showing symptoms of the Minamata disease. Although the mercury exposure is increasing, the threated health conditions of the populations determine the degradation of their resilience. Understanding the distribution and fate of mercury is critical for the mitigation and protection, considering that mercury affects the immune system of vulnerable communities. This review aims to discuss the key issues associated with artisanal goldmining, including contamination of waters, and suspended particulate matter inputs, which promote environmental degradation and harm the health of Indigenous and riparian communities. Notably, between 2023 and 2024, the prolonged burning season in the Amazon rainforest intensified mercury spreading into the atmosphere, further depositing it into terrestrial and aquatic ecosystems, with probable consequences on the methylation of Hg. The biomagnification of mercury in fish, through the trophic chain, as the main path of exposure for humans, was also discussed. Finally, research on biomarkers has shown that a deeper understanding of the biochemical processes within cells could lead to the identification of mercury-protective foods and the development of new therapies and medicines that could mitigate the mercury effects on humans. Mitigation actions are proposed, and it is concluded that large scale Amazon restoration initiatives have to be started, together with regulations for goldmining and enforcement of environmental laws.